Cellular responses in the respiratory tract following intranasal administration of peste des petits ruminant vaccine in goats / Respuestas celulares en el tracto respiratorio después de la administración intranasal de la vacuna contra la peste de pequeños rumiantes en cabras

A trial was conducted to compare the cellular responses in the respiratory tract in intranasal vaccination against caprine Peste des petits ruminant lineage 1 variant virus infection with intramuscular and subcutaneous vaccinations in order to elucidate the mechanism of the protection. Twenty four goats were divided into four equal groups. Group 1 was vaccinated intranasaly, group 2 was vaccinated subcutaneously, and group 3 intramuscularly, while Group 4 was the unvaccinated control group. In each group the vaccinations were carried out once. All goats were challenged intratrachealy with PPR virus at a concentration of 106.5 TCID50 two weeks after vaccination and were euthanised 21 days after the challenge. The bronchoalveolar lavage differential count, bronchial associated lymphoid tissue (BALT) responses were measured using standard techniques. Descriptive Statistics and ANOVA was employed and significance was at p < 0.05. The exposure also resulted into significant increase in the number and size of BALT as well as the number of lymphocytes in BALT. This study showed the mechanism of the protective effect of intranasal vaccination of PPR vaccine observed with the strong mucosal and defensive cellular responses in the respiratory tract observed than the subcutaneous and intramuscular routes.

Se realizó un ensayo para comparar las respuestas celulares en las vías respiratorias después de la vacunación intranasal contra la variante caprina de la infección del virus peste de pequeños rumiantes linaje 1 con vacunas intramusculares y subcutáneas con el fin de dilucidar el mecanismo de protección. Veinticuatro cabras fueron divididas en cuatro grupos iguales. El Grupo 1 fue vacunado por vía intranasal, el grupo 2 vía subcutánea, el grupo 3 vía intramuscular y el grupo 4 control no vacunado. En cada grupo se vacunó sólo una vez. Todas las cabras fueron expuestas al virus peste de pequeños rumiantes por vía intratraqueal a una concentración de 106.5 TCID50 2 semanas después de la vacunación, y fueron sometidos a eutanasia 21 días después. Se midieron el recuento diferencial del lavado broncoalveolar y las respuestas de los tejidos linfoides asociados bronquios (BALT) utilizando técnicas estándar. Los resultados se evaluaron por estadística descriptiva y ANOVA, con una significación p<0,05. La exposición también mostró un aumento significativo en el número y tamaño del BALT, así como el número de linfocitos en este. El estudio mostró que el mecanismo del efecto protector de la vacunación intranasal contra el virus peste de pequeños rumiantes posee una respuesta mucosa y celular defensiva en el tracto respiratorio mayor que la observada por vacunación vía subcutánea e intramuscular.

Comparative histopathology of the lymph nodes, spleen, liver and kidney in experimental ovine trypanosomosis.

The infection of Yankassa rams with three important trypanosome species affecting livestock, namely, Trypanosoma congolense, T. vivax and T. bruceiproduced both acute and chronic fatal conditions. Chronic infections were induced in the three infections by the application of subcurative doses of diaminazene aceturate (Berenil). Pathological changes in the infected animals included splenomegaly and hepatomegaly which were more pronounced in acute than in chronic T. congolense infection. However, these changes were more severe in chronic than in acute T. vivax infection. While splenomegaly was more pronounced in chronic T. bruceiinfection than in acute, hepatomegaly and lymphadenopathy were more severe in acute than in the chronic condition. The increases in size of the spleen, lymph nodes and liver were associated with congestion, increases in cell density related to increased immunological reactions in the spleen and lymph nodes as well as increase in numbers, size and activity of the phagocytic cells in these organs.

Immunodiagnosis of bovine trypanosomiasis in Anambra and Imo states, Nigeria, using enzyme-linked immunosorbent assay: zoonotic implications to human health.

BACKGROUND & OBJECTIVES: The prevalence of trypanosomiasis was studied in cattle, being a major source of animal protein in Nigeria, thus, a very likely means of spread of Human African Trypanosomosis (HAT). METHODS: Enzyme-linked immunosorbent assay (ELISA) was used to diagnose bovine trypanosomiasis in 264 samples collected from adult cattle of mixed breeds, age and sex, in Anambra and Imo states, Nigeria. RESULTS: Out of 264 samples analysed, 21 (7.96%) were seropositive for Trypanosoma congolense while 20 (7.58%) were seropositive for T. vivax and 8 (3.03%) were seropositive for T. brucei infections in both the states. INTERPRETATION & CONCLUSION: The predominant species was found to be T. congolense. Mixed infection of three species, T. vivax, T. congolense and T. brucei was found to dominate other mixed infections in both the states. ELISA detected the infection of the three species of trypanosomes in the same group of animals. The usefulness of antigen capture ELISA in the diagnosis of human or animal trypanosomiasis was established, and the possibility of the spread of HAT caused by T. brucei gambiense and T.b. rhodesiense through cattle was expressed.

In vitro erythrophagocytosis by cultured macrophages stimulated with extraneous substances and those isolated from the blood, spleen and bone marrow of Boran and N'Dama cattle infected with Trypanosoma congolense and Trypanosoma vivax.

A standard radioactive chromium (51Cr) release assay was used to assess the in vitro phagocytosis and lysis of bovine erythrocytes by cultured splenic, bone marrow and peripheral blood monocyte-derived (PBM) macrophages isolated from healthy and Trypanosoma congolense and T. vivax-infected cattle of the Boran and N'Dama breeds. Recombinant cytokines (rHuTNF-alpha and rBolFN-gamma) and non-acid-dialysed peripheral blood mononuclear cell (PBMNC) culture supernatants stimulated these PBM for enhanced activities. The stimulants caused increases in the rate of erythrocyte phagocytosis and lysis by cultured PBM in a concentration-dependent manner. But very high stimulant concentrations caused deceased in vitro erythrophagocytosis. However, bacterial lipopolysaccharide (LPS) and acid-dialysed PBMNC culture supernatants did not cause any increase in cultured PBM erythrophagocytosis. In vitro erythrocyte phagocytosis and lysis by splenic, bone marrow and peripheral blood monocyte (PBM)-derived macrophages of Boran breed of cattle infected with Trypanosoma congolense increased from 14 days post-infection (DPI) onwards and thereafter maintained at various levels above pre-infection. Cultured splenic macrophages showed the greatest erythrocyte destruction capability while PBM-derived macrophages was the least. The rates of in vitro erythrocyte phagocytosis and lysis were higher with the cultured PBM of the Boran than those of the N'Dama cattle during T. congolense infection. The rate of in vitro erythrocyte destruction was however, similar in both groups of cattle during T. vivax infection. These results correlated positively with the dynamics and degree of anaemia developed by these groups of animals during both T. congolense and T. vivax infections. Cattle infected with T. congolense and T. vivax developed varying degrees of normocytic normochromic anaemia during infection. Boran cattle developed a more severe anaemia, and had to be treated with diminazine aceturate, than N'Dama cattle during T. congolense infection. Both breeds of cattle developed a milder but similar degree of anaemia during T. vivax infection. None of the animals were treated. The results of this study indicated a role of in vivo macrophage stimulatory factors, notably cytokines such as TNF-alpha and IFN-gamma in host's serum, as well as parasite antigens, which may act singly or in concert, in the process of enhanced erythrocyte destruction, hence anaemia by the mononuclear phagocytic system (MPS) during bovine trypanosomosis.

Differential expression of surface membrane antigens on bovine monocytes activated with recombinant cytokines and during Trypanosoma congolense infection.

The expression of surface membrane antigens on peripheral blood monocytes (PBM) of cattle of the Boran and N'Dama breeds activated with recombinant cytokines (TNF-alpha and IFN-gamma) and during experimental infection with Trypanosoma congolense was investigated using monoclonal antibodies (MoAbs) and fluorescein-activated cell sorter (FACS). The surface antigens investigated were C3bi receptor, major histocompartibility (MHC) II complex (Ia antigen) and two monocyte/macrophage (Mphi) differentiation antigens. The study revealed that both cytokines caused the enhancement of the expression of all the PBM surface antigens studied. rBolFN-gammaat low concentrations was more efficient in causing the activation of PBM. While the PBM of Boran cattle were more significantly activated to express the C3bi receptor vis-à-vis the Ia antigen than N'Dama cattle, the reverse was the case with the PBM of N'Dama cattle which expressed more Ia antigens than Boran PBM. Similar results were observed during T. congolense infection in the two breeds of cattle. The significantly higher expression of C3bi receptor and correspondingly lower Ia antigen expression by the PBM of Boran cattle, both during trypanosomosis and in vitro may be responsible for the higher rate of erythrocyte phagocytosis, hence the development of more severe anaemia by Boran cattle during trypanosomosis than N'Dama. In addition, the expression of significantly higher numbers of Ia antigen by N'Dama Mphi, hence are more able to process, present and initiate better trypanosome antigen-specific immune response than Boran cattle during infection. These two attributes are known genetic characteristics of trypanotolerance in cattle.

Leucocyte and thrombocyte responses in dogs experimentally infected with Trypanosoma brucei.

Three dogs were subcutaneously infected with Trypanosoma brucei strain ILRAD 1797. Artificial haemolytic anaemia was induced in 2 other dogs by phlebotomy, heat treatment and re-infusion of the blood, while 2 dogs were kept as control animals. The infected animals developed pan-leucopenia and thrombocytopenia, while the dogs with artificial haemolytic anaemia developed leucocytosis and thrombocytosis. These findings suggest that there was a bone marrow depressing factor in the plasma of T. brucei-infected dogs especially as it affected leucocyte production.

Haematological changes in ewes experimentally infected with Trypanosoma brucei.

Changes in the haematological values were studied in West African Dwarf ewes infected with Trypanosoma brucei. This disease was characterized by a normocytic normochromic anaemia in the acute phase and a severe macrocytosis during the chronicity. The observed changes suggest inadequate erythropoiesis in the acute phase while the chronic phase had a superior but still inadequate erythropoietic response with persistent anaemia. Normal total leucocyte values were observed during the acute phase while leucocytosis was a permanent feature in the chronic phase.

Serum biochemical changes in West African Dwarf sheep experimentally infected with Trypanosoma brucei.

Serum and plasma biochemical values were determined in female West African Dwarf sheep experimentally infected with Trypanosoma brucei. The results show an increase in the values of serum iron, chloride, bicarbonate, inorganic phosphate, creatinine, urea, total protein, globulin and plasma fibrinogen. The serum albumin, albumin/globulin ratio, potassium, copper and magnesium values are depressed. These findings suggest detective re-utilization of iron in erythropoiesis and probable paratathyroid gland, hepatic and/or renal malfunction.

Ultrastructure of developing and mature caprine leukocytes.

Transmission electron microscopy demonstrated that, based on the structural uniqueness of the granules, caprine granulocytes are easily distinguishable from each other from the promyelocyte stage onwards. The neutrophils had the smallest granules which varied in size and were, in mature cells, either spherical to dumb-bell in shape; in mature cells the granule contents were compact and finely granular. The primary granules were smaller than the secondary granules. The eosinophil granules were large and typically had internal crystalloid structures; a second group of spherical granules with moderately coarse non-crystalloid sub-structure was present in smaller numbers in promyelocytes and myelocytes only. The basophil granules were also large, lacks crystalloids but showed variation in coarseness of granule substance, ranging from finely granular to markedly coarse. Mature granulocytes lacks Golgi apparatus and rough endoplasmic reticulum and ribosomes which were present in promyelocytes, myelocytes, metamyelocytes and bands. The monocytes had moderate numbers of spherical granules, rough endoplasmic reticulum, mitochondria and ribosomes, as well as prominent Golgi apparatus, and the cytoplasm had many small vacuoles.

A light and electron microscopic study of changes in blood and bone marrow in acute hemorrhagic Trypanosoma vivax infection in calves.

Eleven 6-month-old calves were tsetse fly challenged with a stock of Trypanosoma vivax (IL 2337) that causes hemorrhagic infection. The calves were randomly euthanatized every 4 to 6 days; two other calves served as controls. Peripheral blood changes included anemia, thrombocytopenia, and an initial leukopenia. Later in the course of infection, leukocytosis associated with lymphocytosis and neutropenia developed. Moderate reticulocytosis (highest mean count 3.6 +/- 3.7%, maximum count 9.4%) accompanied the first wave of parasitemia, but poor response (highest mean 0.4 +/- 0.0%) occurred during the second wave, despite the persistence of severe anemia. Light microscopic examination of bone marrow samples showed a drop in the myeloid: erythroid ratio with a decrease in granulocytes, particularly metamyelocytes, bands, and segmenters. Increase in lymphocyte counts corresponded with the appearance of lymphoid nodules within the marrow. Megakaryocytic volume increased significantly in infected animals, and some megakaryocytes showed emperipolesis of red cells, neutrophils, and lymphocytes. Transmission electron microscopic examination of the bone marrow revealed that trypanosomes had crossed the sinusoidal endothelium into the hematopoietic compartment as early as the second day of parasitemia. Macrophages proliferated in the bone marrow; and from the second day of parasitemia until the end of the experimental infection, on day 46, the macrophages had phagocytosed normoblasts, eosinophil and neutrophil myelocytes, metamyelocytes, bands, and segmenters, as well as reticulocytes, erythrocytes, and thrombocytes. Therefore, dyserythropoiesis and dysgranulocytopoiesis were responsible, in part, for the observed anemia and granulocytopenia, respectively.

Erythrocyte response to Trypanosoma brucei in experimentally infected dogs.

Trypanosoma brucei infection produced an acute and fatal disease in Nigerian mongrel dogs due to a rapidly developing anaemia. Infected dogs responded with increased reticulocytosis, which was not sustained with chronicity. In comparison the response to artificially-induced haemolytic anaemia was progressive, marked and sustained. The anaemia of T. brucei infection of dogs was either normocytic normochromic in acute infection or microcytic normochromic in chronic infection. Artificially-induced haemolytic anaemia was either macrocytic normochromic or normocytic normochromic. The erythropoietic potential of plasma in vivo in mice increased in T. brucei-infected dogs except at the terminal parasitaemia. The anaemia in Trypanosoma brucei-infected dogs is therefore initially responsive but becomes poorly involved with chronicity.

Haematology of experimental Trypanosoma brucei gambiense infection. II. Erythrocyte and leucocyte changes.

Chronic Trypanosoma b. gambiense infection of rabbits induced mild anaemia which was initially macrocytic normochromic, but became later microcytic hypochromic. Moderate anisocytosis and poikilocytosis were evident from 14 days post infection (p.i.). Nucleated red cells which were observed prior to the infection (normal feature of rabbits) declined in number as the infection progressed. Leucocytosis with neutrophilia, eosinophilia, monocytosis and terminal lymphopaenia were also observed. The main changes in the morphology of leucocytes were the presence of atypical lymphocytes as well as increased levels of band neutrophils in the peripheral circulation. It is concluded that the main erythrocytic and leucocytic changes in the T.b. gambiense infection were mild anaemia which was terminally microcytic hypochromic and transient leucocytosis due to neutrophilia and monocytosis.

Platelet aggregation inhibition in Trypanosoma vivax infection of sheep.

We have investigated in vitro platelet aggregation in platelet rich plasma from Trypanosoma vivax infected and control sheep using the dual channel Payton Aggregometer. Final concentrations of the following inducing agents were used: 1.2 um ADP, 6.2 ug collagen, 1.2 ug ristocetin and 1 u thrombin. These showed that there was a significantly reduced aggregation of platelets from infected sheep (13.4 +/- 1.1 pc at week 3 post infection when compared with control sheep PRP 95.0 +/- 1.0pc; P less than 0.001) using ADP. Similar differences were also obtained with other inducing agents. Preliminary 14C-5HT uptake and release studies showed that there was difference in the uptake of label between platelets from infected (18.6pc) and control (28.4pc) sheep. However, when release was inducted, comparable results were obtained for both infected and control sheep platelets. It is concluded that the degree of aggregation inhibiting varies directly with the level of parasitaemia.

Response to anaemia in experimental Trypanosoma vivax infection of sheep.

Trypanosoma vivax produced a progressive macrocytic normochromic anaemia in sheep during the acute phase of infection. Reticulocytes were absent from the blood of healthy sheep and of sheep with T. vivax-induced anaemia. However, anaemia induced artificially (AHA) in sheep by in vitro heat treatment of red cells, which was comparable in classification and degree to the anaemia of T. vivax infection, produced a reticulocytosis of 1.5 +/- 1.0 per cent. When plasma from the anaemic blood of sheep infected with T. vivax for two and four weeks was inoculated subcutaneously into mice, the reticulocyte response was similar to that of mice that received no sheep plasma and inferior to that elicited by normal sheep plasma. The anaemic plasma from sheep infected with T. vivax for three weeks induced a moderate reticulocyte response in mice which was, however, less intense than that induced by plasma from sheep with artificially induced anaemia of comparable intensity. These results indicate that, although the macrocytosis suggests that T. vivax-induced anaemia in sheep is slightly responsive, this response is suboptimal since reticulocytes were lacking in the blood of the sheep and their plasma was weakly erythrogenic in mice. This contrasts with the mild reticulocytosis in sheep with AHA of the same intensity and classification, whose plasma also stimulated considerable erythropoiesis in mice. The poor stimulation by plasma from T. vivax-infected sheep at two and four weeks post-infection suggests subnormal erythropoietin at these periods of infection.

Leucopenia in Trypanosoma vivax infection of sheep.

Experimental Trypanosoma vivax infection of sheep produced a moderate leucopenia associated with a lymphopenia and eosinopenia. The total white blood cell counts of adult mice were not significantly depressed when inoculated with plasma from T. vivax-infected sheep. These observations suggested that the plasma of the infected sheep did not have a factor which could depress leucopoiesis in vivo.

Pathogenesis of Trypanosoma brucei infection in deer mice (Peromyscus maniculatus). Ultrastructural pathology of the spleen, liver, heart, and kidney.

Trypanosoma brucei EATRO 110 infection of the deer mice (Peromyscus maniculatus) produced moderate to marked lesions in the spleen, liver, heart, and kidney seven to ten weeks after infection. Splenic lesions consisted of marked splenomegaly, with infected spleens weighing 25.9 times control spleens. Transmission electron microscopy of the sinuses and Billroth's cords of the splenic red pulp demonstrated an increased cellularity with greater contact between cells due partly to proliferation of macrophages, transformed lymphocytes and plasma cells and partly to accelerated erythropoiesis with increases in the numbers of rubricytes and reticulocytes. Erythrocytes also were present in large numbers, and erythroclasis was accelerated. Hepatic lesions consisted of necrosis of few hepatocytes, proliferation and hypertrophy of Kupffer's cells which exhibited increased phagocytosis--particularly of erythrocytes, as well as perivascular cuffs consisting of lymphocytes, plasma cells and macrophages. Myocarditis was marked and was characterized by degeneration of myocardial fibers with decreases in mitochondrial size and myofibril contents and fragmentation of some degenerating fibers, and was accompanied by accumulation of inflammatory cells including lymphocytes, transformed lymphocytes, plasma cells, and macrophages between the myocardial fibers. Renal lesions consisted of severe glomerulonephritis characterized by deposition of electron dense material along the basement membrane and in the mesangium of the glomerular tufts, and less frequently beneath the basement membrane and visceral epithelium of the Bowman's capsule and within the peritubular vessels. Neutrophils with fewer macrophages and lymphocytes invaded the glomeruli.(ABSTRACT TRUNCATED AT 250 WORDS)